1. Field
Embodiments relate to a rechargeable secondary battery.
2. Description of the Related Art
A rechargeable lithium ion secondary battery may be used, for example, in a small-sized electronic device, such as a notebook computer or a cellular phone. Also, because recently developed rechargeable lithium ion secondary batteries have advantageous characteristics, including high output power, high capacity, and lightness in weight, as compared to other types of rechargeable secondary batteries, they are widely used in hybrid vehicles or electric vehicles.
Here, because the rechargeable lithium ion secondary battery used in a hybrid vehicle or an electric vehicle has relatively high capacity, a safety device for protecting against external short-circuit or over-charge is provided in the rechargeable lithium ion secondary battery. The safety device may cut off a charge or discharge path when the external short-circuit or over-charge occurs to the rechargeable lithium ion secondary battery.